Search results: set consistent view mode [localgov_guides]

[finnlewis]

As part of reviewing the search functionality, it has become apparent that there is no consistent presentation of search results across the distribution.

We need to

• ensure each content type has a search_result display node
• configure the search_result display mode to have the appropriate fields

In the case of localgov_guides, we need to ensure appropriate configuration for

• localgov_guides_overview
• localgov_guides_page